$(2)(7$ points$)$ For this question, you should make reasonable numerical approximations if needed.

$($a$)$ Consider the circuit below. For the switch is closed, and the system has reached steady state. At time $t=0s,$ the switch opens.

Find the current $i_a$ at time $t=0^{-}s($i$.$e$.,$ immediately before the switch opens$).$

Find the current $i_a$ at time $t=0^{+}$s $($i$.$e$.,$ immediately after the switch onens$).$

$i_a(0^{-}s)$

$i_a(0^{+}s)$

$($b$)$ Consider the circuit below. For the switch is in position $1,$ and the system has reached steady state. At time $t=0s,$ the switch moves to position $2($and stays there$).$ Just before the switch moves, $i_x$ is $4$ A $.$

Find the current $i_b$ at time $t=0^{+}s($i$.$e$.,$ immediately after the switch moves to position $2).$

Find the current $i_b$ at time $t=2s.$

Find the current $i_b$ at time $t=.$

$($c$)$ Consider the circuit below. For the switch is open, and the system may not have reached steady state. At time $t=2$ s $,$ the switch closes. Just after the switch closes, $i_c$ is $5$ A $.$

Find the current $i_c$ at time $t=$

Find the current $i_c$ at time $t=lon$

$i_b(0^{+}s)$

$i_b(2s)$

$i_b()$

$i_c(4s)$

$i_c(6s)$